I think Nintendo diehards were one group. The other big group was kids. Nintendo home consoles are always loved by kids. (Not sure if you consider kids to also be Nintendo diehards.)
I wasn't going to get a Wii U, but my daughter kept begging and gave me big, sad puppy-dog eyes. So I caved and bought a Wii U. It was the successor to the Wii. so I understand why she wanted one. Nintendo consoles are always popular with kids, but the exceptional ones manage to be popular with everyone else too.